ESP32-S3 "pad JTAG" port without burning efuses?
Posted: Wed Aug 13, 2025 1:27 am
Hi all,
Is there a way to enable discrete "pad JTAG" access, without burning any efuses on the chip?
There's a sentence in the reference manual that says "The CPU JTAG signals can be routed [...] using eFuses and when the user program has started, software control as well":
However, I can't find any memory mapped addresses for these ctrl_sel registers: maybe it's only the "USB_JTAG_BRIDGE_EN" function that's available to software control?
(Use case is: trying to JTAG debug an issue with USB support in MicroPython, so we need the USB port to be muxed to native USB. Don't want to sacrifice a board by burning efuses, if we can help it.)
Is there a way to enable discrete "pad JTAG" access, without burning any efuses on the chip?
There's a sentence in the reference manual that says "The CPU JTAG signals can be routed [...] using eFuses and when the user program has started, software control as well":
However, I can't find any memory mapped addresses for these ctrl_sel registers: maybe it's only the "USB_JTAG_BRIDGE_EN" function that's available to software control?
(Use case is: trying to JTAG debug an issue with USB support in MicroPython, so we need the USB port to be muxed to native USB. Don't want to sacrifice a board by burning efuses, if we can help it.)